Hull vs. line voltage

[Salty]

Like Crawfish post

[Lulu]

Bonding: Simplest way to bond a boat is to run a section of 3/4" copper pipe through the boat. Flatten the ends and drill #8 or #10 holes to attach the wires with SS sheet metal screws to the things that need to be bonded; like rudder, shaft, fuel tanks, through hull fittings, the shoe, metal poles or mast, etc. Main led goes to the engine because that is the largest piece of metal on the boat. Most import detail is to keep the connections clean and dry. Heat shrink, Sykoflex, grease all work, but make it simple and easy to access so you can trouble shoot fast. Any sign of corrosion needs to be cleaned. Any white precipitate means there is current. You need to find out why and fix it. The green stuff is normal oxidation of the copper, no big deal just keep it cleaned off. Don't !!! use silicon based sealer, it doesn't hold up. A top notch installation would be a 1/0 or 2/0 wire ran through the boat connected to busses for the connections, but it is more expensive. Always use 14 gauge wire. The voltage is small, but you want to maximize the impedance (ability of the current to run uninhibited).


Al anodes: I added Aluminum anodes to the rudder two seasons ago; one 8 pounder on each side. They go fast (steel boat) and I send a diver down about once a month to scrub them. I talked with Malcolm Russell about this in Dec 2014. He told me the Al anodes burn deep into the plate. It's best to replace them several times during the season to keep them as active as possible. I'm adding two more Al anodes to the hull just above the prop this season because when I keep the zincs and Al anodes clean the boat produces better. I can usually tell when I need to send the diver down cause the trip isn't as productive as I thought it should be. Also, I add small zincs to the fins on the floppers. You'll be surprised how fast they go. My belief is they help the snooters catch better (I might be dreaming on this one.)

Thing about Malcolm is he's forgotten more about the boat's electrical field and how to manage it than most of us will ever know. I find it productive to spend an hour (or two) on the phone reviewing my readings and asking a lot of questions. More times than not I get, "Didn't I tell you about that?" The thing is he's always experimenting with the tuna and salmon boats, he has an incredible following, and doesn't know how current you are with changes he has made in his thinking based on productive changes made in the respective fleets. You have to ask questions, lots of them.

[Crawfish]

Bonding: Simplest way to bond a boat is to run a section of 3/4" copper pipe through the boat. Flatten the ends and drill #8 or #10 holes to attach the wires with SS sheet metal screws to the things that need to be bonded; like rudder, shaft, fuel tanks, through hull fittings, the shoe, metal poles or mast, etc. Main led goes to the engine because that is the largest piece of metal on the boat. Most import detail is to keep the connections clean and dry. Heat shrink, Sykoflex, grease all work, but make it simple and easy to access so you can trouble shoot fast. Any sign of corrosion needs to be cleaned. Any white precipitate means there is current. You need to find out why and fix it. The green stuff is normal oxidation of the copper, no big deal just keep it cleaned off. Don't !!! use silicon based sealer, it doesn't hold up. A top notch installation would be a 1/0 or 2/0 wire ran through the boat connected to busses for the connections, but it is more expensive. Always use 14 gauge wire. The voltage is small, but you want to maximize the impedance (ability of the current to run uninhibited).


Al anodes: I added Aluminum anodes to the rudder two seasons ago; one 8 pounder on each side. They go fast (steel boat) and I send a diver down about once a month to scrub them. I talked with Malcolm Russell about this in Dec 2014. He told me the Al anodes burn deep into the plate. It's best to replace them several times during the season to keep them as active as possible. I'm adding two more Al anodes to the hull just above the prop this season because when I keep the zincs and Al anodes clean the boat produces better. I can usually tell when I need to send the diver down cause the trip isn't as productive as I thought it should be. Also, I add small zincs to the fins on the floppers. You'll be surprised how fast they go. My belief is they help the snooters catch better (I might be dreaming on this one.)

Thing about Malcolm is he's forgotten more about the boat's electrical field and how to manage it than most of us will ever know. I find it productive to spend an hour (or two) on the phone reviewing my readings and asking a lot of questions. More times than not I get, "Didn't I tell you about that?" The thing is he's always experimenting with the tuna and salmon boats, he has an incredible following, and doesn't know how current you are with changes he has made in his thinking based on productive changes made in the respective fleets. You have to ask questions, lots of them.

What did he mean by "Al anodes burn deep into the plate" ?

[Scotthmt]

Lulu, thank you for all the information you've shared here. Answers to some of these questions are like pulling teeth sometimes. I have rebonded my boat and I ran everything to a bus bar, hopefully should make it easier to clear up any future issues.

[Lulu]

There are two questions: 1.) Aluminum (Al) anodes burning deep in the plate, and 2.) using a bus bar for the bonding system.

1.) The zincs or Al anodes serve the same basic purpose, in fact the zincs are technically an anode as well. Their purpose is to sacrifice free electrons produced by the galvanic activity created between two dissimilar metals. In other words the electrical potential between two different metals will create a battery like effect. You've heard of not leaving a penny (copper) on an aluminum deck, it will eat a hole in the deck? The anodes are giving up free electrons to the rudder (steel), through hull fittings (usually brass which is ~60% copper), shaft (steel or SS), etc. That is why the zinc diminish over time and need to be replaced. The Al anodes sacrifice much faster than zinc because they have an extra electron to loose (you can take my word for it or look it up on a periodic table or in a chemistry book) What was meant by burning deep is the galvanic activity goes deep into the Al plate (anode) to the point that the participate (white stuff) can not be thoroughly scrubbed off, reactivating the anode. The recommendation is to replace the Al plate instead of trying to reactivate by scrubbing with a SS brush.

2.) There is nothing wrong with using a buss bar. It actually makes it easier to monitor and clean the connections because half of the connections are in one place. One note is use at least 14 guage tin coated marine grade wire. (recommend using a standard color like green so you know which wires do what) The wire runs can sometimes be long and you do not want to restrict the electrical flow (minimize impedance). When I rewired (and the reason for rewiring) I found house grade wire with multiple splices using 16 and 18 guage wire. The battery cables were 10 guage from an auto shop; no wonder stuff wasn't working and the hull potential wasn't where it should have been. Up grading the wire and eliminating the splices (which increases impedance) solved the problem. Remember, there are two reasons for having a good bonding system. 1.) it helps protect your boat (save money spent on repairs). And 2.) it helps your boat realize its optimal hull potential which has a direct impact on the boat's productive (catch fish/make money).

Probably asking why use Al and zinc anodes? Very simply, Zinc are used to protect the boat. The Al anodes increase the hull potential. There are a couple of earlier postings on hull potential and line voltage.

[Once and Future]

Lulu: You know way more about making boats more fishy with electricity than I do, and I very much appreciate your detailed lessons. But you have me a bit confused above with your use of the word "impedance".

Impedance "impedes" the flow of electricity, so I guess you mean removing the splices in the wire reduces impedance, correct? (Not trying to be a grammar Nazi, just trying to make a confusing subject less confusing.)

[Kelper]

Anybody have any experience dialing in aluminum boats with nylon spood gurdies?

[SalmonSeeker]

Lulu, will the addition of aluminum, in addition to your normal complement of zincs anodes, lead to the same result as over zincing the boat; especially the wood hulls?

[Lulu]

Impedance: A measurement of the total opposition to current flow. We want to achieve a low impedance for the bonding system and black box (if you use one). We want any current generated at point A gets to point B. Any restriction, like scale build up on the connectors or bad wire, increases impedance thus lowering the amount of voltage conducted. Lowering the impedance is accomplished by keeping the connectors clean and water tight, increasing the gauge of the wire (the more clean wire strands the current has to flow through the freer it will flow), illuminating splices in the wire (most connectors are made of aluminum, aluminum does not conduct as well as copper, therefore creating a restriction of the current. The more splices in a wire run the higher the impedance).

I can't answer the question of adding Al anodes to a wood boat with assurance. My experience is with steel. What little I know is the Al anodes will go fast. The forward motion of the boat while your fishing a season will lower the hull potential and minimize any negative affects on your fasteners. By the end of the season the Al anodes will be used up and should be not a concern. One nagging thought is begin careful the boat is zinced properly. The best answer I have is call Malcolm Russell, he'll know and tell you exactly how to do it. (250) 213-3440. Same with an aluminum boat.

[Scotthmt]

My black box arrived yesterday and I installed it today. Since there are no pictures online of what it looks like I figure I'll post one.

[Lulu]

Top of the line. I've tried the pulse mode, but didn't see much difference. I think it works better for silvers and pinks who like the line voltage higher than Kings. Neat thing is the digital readout is accurate and you always know what's going on with your gurdies. Don't get too "wigged out" if you have a reading when nothing is in the water, but the gurdies are wet (usually around .150-.200). Usually see this in the morning when the fog as everything wet. That is the dissimilar metal in the gurdies and the water allowing a path for the current. When everything is dry, you should read .000. If everything is dry, the gear is on the deck, and you have a reading you know your isolation has failed. Re-set the bolts after cleaning them and cover the bolt heads with Sika-Flex so water can not migrate into the threads creating an electrical pathway.

If you see your box reading changing while your fishing, look to see if your wire is shorting out around the blocks. I insulates the shackels that secure the blocks to the davits with heat shrink. I have a tee off the davit. I line the outside of the tee with rubber hose. (I found that in a turn the float wire will rub on the tee causing a short in the system.) Fish don't like things to change. 1/4" fuel line hose works great.

[Scotthmt]

Sitting on a trailer in my driveway and pretty dry I have a reading of .005 I assume this is normal.

[Lulu]

Nothing to worry about. That's 5/1,000's of a volt. Start looking around when your dry and over .100

[Salty]

I attach my gurdies to the insulator board with nylon bolts. I attach my blocks to my Davits with nylon bolts and washers. It is amazing how saltwater, metal, and a bit of rust can start compromising your isolation. I also wash my gurdies and mounts with fresh water whenever I unload or tie up in my stall.

[Lulu]

Salty, you may do this: I use Sika-Flex on the bolt head.. I cover the entire bolt head and all around the gurdie base, it is not pretty. Sika-Flex holds better than silicon based sealants like 5200. Even at that, I have to watch any salt intrusion over the season. I can generally tell something is going on because the base line voltage creeps up in the morning before I through the gear in the water. And, my hull potential slips a little. It never fails, check all 16 bolts and it is the last one that failed with green stuff all over the bolt threads. Down side is Sika-Flex is tough to work with. Got to cut the stuff off and wire wheel the threads or replace completely.

[Lulu]

Check your testing gear. Just hauled out the boat and checked hull potential. Potential was slightly below normal and dropping. BIG problem!! With new zincs and fresh paint, hull potential should be higher than normal and volt meter should go up until it stabilizes; usually takes 5-10 minutes. Checked testing leads and found connections corroded and exposed wire turning green; not good. Replaced with new testing terminals and wire. Guess what?! Hull potential is were is should be and moving up like it suppose to. Check your testing gear including battery in volt meter!!!! Good readings this time of year are your base line for the season, the only way you can trouble shoot problems as the season progresses.

[Salty]

Lulu, no problems with the nylon bolts. I used Sika flex whenever I was using stainless bolts. I change my Aluminum anodes every 6 months. But, I fish every month.

[Scotthmt]

I just splashed my boat the other day the numbers I got were
In the water engine off battery on .95x
In water engine on .85x

New zincs new bottom paint, rear painted with bottom of the can.

The numbers were climbing slowly on the thousandths, .851, .852, .853 etc etc

I think it's where it should be, I haven't done a in gear number run yet.

[Lulu]

I'm told that the target hull potential at the dock is over .800 volts. Looks like you're in the range. One last reading is with the boat in gear at the dock. I loose about .04 volts with this reading. The reason is the prop is pulling water over the hull which causes the electrons freed from the galvanic activity to flow in a more linear direction (i.e. behind the boat) vs at the dock were the electrons are attracted to the zinc, giving the slightly higher reading.

Just checked shaft brush connections. Had to make a new lead cause everything was rushed and dirty. Another project! Check rudder bonding.

[Abenal]

Regarding Lulu's posts about bottom paint: I'm getting hauled and sandblasted this winter or early spring. I will use 2 coats of Ameron 235 epoxy for a barrier coat, then apply the antifouling bottom paint over that. The professional painter has in stock bulk Ameron 214 ablative bottom paint with a copper content of 68%. Would this high copper content ablative paint work as well as the Trinidad Pro hard bottom paint Lulu used? I asked the painter about using Trinidad Pro hard bottom paint and he wasn't sure that it would adhere to the epoxy barrier coat. He knows that his Ameron 214 ablative is compatible with and adheres to the Ameron 235 epoxy barrier coat.

My point is: isn't the copper content of the bottom paint what is important here? Or am I missing something about the hard paint versus ablative? Of course this is all from a fishing perspective and how the bottom paint affects the electrical field around the boat.

I'm trying to get in touch with Ameron tech support to find out if the two paints are compatible, they will probably tell me to use their version of bottom paint instead of Pettit Trinidad Pro.

Thanks for any comments or input that you might have.